Influence of Nanoparticle Size on Strain at the Core-Shell Interface

2015 ◽  
Vol 662 ◽  
pp. 217-220 ◽  
Author(s):  
Ondrej Milkovič ◽  
Jana Michaliková ◽  
Jozef Bednarčík ◽  
Štefan Michalik
Keyword(s):  
Solid State ◽  
High Energy ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Structure Of Nanoparticles ◽  
Fe Nanoparticles ◽  
Hall Method ◽  
Core Shell Structure

This work deals with the strain at the core-shell interface of Fe nanoparticles. Series of Fe nanoparticles with various mean diameters were prepared by precipitation in solid state in binary Cu-Fe alloy. Further, nanoparticles were isolated by dissolution of Cu matrix. High-energy X-ray diffraction (XRD) was used to probe structure of nanoparticles. XRD measurements suggest presence of the core-shell structure, where core and shell of the nanoparticles are formed of α-Fe and CuFe2O4 phase, respectively. Strains in core and shell were estimated as a function of nanoparticles size by Williamson-Hall method.

Controlled Synthesis of Core-Shell Structure SiO2 /NaGdF4:Eu3+ Magnetic and Optical Bifunctional Composite

2014 ◽  
Vol 936 ◽  
pp. 359-363
Author(s):  
Yan Li Wu ◽  
Min Liao ◽  
Hai Xin Ding ◽  
Ru Chun Yang ◽  
Dan Dan Xiong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Shell Structure ◽  
Photo Luminescence ◽  
Core Shell ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Composite

The SiO2/NaGdF4:Eu3+ core/shell composite was prepared by a template-mediated method, making monodispersed SiO2 as core and NaGdF4:Eu colloids as shell, the morphology and the core-shell structure of the resulting particles were analyzed by SEM,X-ray diffraction, and the photo-luminescence and magnetic properties of the microspheres were investigated too. The results shows the composite have great potential to be used as homogeneous magnetic/optical bifunctional material.

Synthesis and Micro-Wave Absorption Properties of BiFeO3 Coated Fe Nanocapsules

2013 ◽  
Vol 712-715 ◽  
pp. 229-232 ◽  
Author(s):  
Gui Mei Shi ◽  
Da Wei Lu ◽  
Yan Zhang
Keyword(s):  
Reflection Loss ◽  
Photoelectron Spectrum ◽  
Core Shell ◽  
Absorber Thickness ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Thickness Layer

BiFeO3coated ferromagnetic Fe nanocapsules is synthesized by arc-discharging method. Typical HRTEM images show that the nanocapsules form in a core-shell structure. X-ray photoelectron spectrum (XPS) and X-ray diffraction (XRD) reveal that the core is ferromagnetic Fe, while the shell is BiFeO3/Bi2Fe4O9.The reflection loss R of less than -10 dB was obtained for the whole frequency within the 2-18GHz range by choosing an appropriate layer thickness between 1.0mm and 7.0mm. An optimal reflection loss of -21.5 dB was reached at 10.6 GHz with an absorber thickness of 2.0mm. It is worth noticing that the BiFeO3coated Fe nanocapsules have two absorption peaks below -10 dB at each thickness layer ranging from 4.0nm to 7.0nm, which means the composites nanocapsules absorber simultaneously are able to absorb microwaves in different band of several GHz.

Annealing Behaviour of Fe-C-N Nanopowder: Formation of Iron/Graphite Core-Shell Structured Nanoparticles

2005 ◽  
Vol 482 ◽  
pp. 187-190 ◽  
Author(s):  
B. David ◽  
N. Pizúrová ◽  
O. Schneeweiss ◽  
Petr Bezdička ◽  
J. Filip ◽  
...  
Keyword(s):  
Gas Phase ◽  
Iron Nanoparticles ◽  
Magnetic Measurements ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Graphite Nanoparticles ◽  
The Mean ◽  
Core Shell Structure

We are reporting the core-shell structured iron/graphite nanoparticles formed by annealing of a nanopowder. The original Fe-C-N based nanopowder has been synthesized by the laser pyrolysis of gas phase reactants. TEM, XRD, Raman spectroscopy, Mössbauer spectroscopy and magnetic measurements were used for its characterization. Nanopowder was heated up to 800°C at ~ 1 Pa vacuum. Presence of iron nanoparticles with the mean diameter of 40 nm in the annealed state of the nanopowder was confirmed from the width of α-Fe X-ray diffraction lines and their core-shell structure was observed under TEM.

Direct Verification of the Core−Shell Structure of Shell Cross-Linked Micelles in the Solid State Using X-ray Photoelectron Spectroscopy

Langmuir ◽  
2002 ◽  
Vol 18 (21) ◽  
pp. 7780-7784 ◽  
Author(s):  
Shiyong Liu ◽  
Yinghua Ma ◽  
Steven P. Armes ◽  
C. Perruchot ◽  
J. F. Watts
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray ◽  
Direct Verification ◽  
The Core ◽  
Core Shell Structure

USE OF SANS AND SAXS IN STUDY OF NANOPARTICLES

2005 ◽  
Vol 04 (05n06) ◽  
pp. 987-994 ◽  
Author(s):  
P. S. GOYAL ◽  
V. K. ASWAL
Keyword(s):  
Small Angle ◽  
Shell Structure ◽  
Small Angle Neutron Scattering ◽  
Core Shell ◽  
X Rays ◽  
X Ray ◽  
The Core ◽  
X Ray Scattering ◽  
Structure Of Nanoparticles ◽  
Core Shell Structure

Small Angle Neutron Scattering (SANS) and Small Angle X-ray Scattering (SAXS), anong other available techniques, are the nost sought after techniques for studying the sizes and shapes of nanoparticles. The contrast between particle and its surrounding is different for X-rays and neutrons. Thus a combined SANS and SAXS study, at times, provides information about the core and the shell structure of nanoparticles. This paper gives an introduction to the techniques of SANS and SAXS and shows results of a study of core-shell structure for a micelle (nanaoparticle of organic material).

The Microemulsion Method for Preparing TiO2 Coated SiO2 Core-Shell Particles

2014 ◽  
Vol 602-603 ◽  
pp. 59-62
Author(s):  
Jing Xie ◽  
Le Fu Mei ◽  
Li Bing Liao ◽  
Guo Cheng Lv ◽  
Zhi Guo Xia ◽  
...  
Keyword(s):  
Shell Structure ◽  
Sintering Temperature ◽  
Phase Changes ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Particles ◽  
Morphology Changes

In this paper, the monodisperse TiO2 particles and TiO2 coated SiO2 core-shell particles were prepared by the method of microemulsion, and the phase and morphology of TiO2 and TiO2 coated SiO2 core-shell structure particles were analyzed by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). At the same time, the phase changes and morphology changes of the two different kinds of structural particles as the changes of sintering temperature were compared. The results show that when the TiO2 particles were prepared by the method of microemulsion, the content of anatase TiO2 decreased gradually and the rutile TiO2 increased gradually as the sintering temperature increases from 550 °C to 650 °C; the core-shell particles of TiO2 coated SiO2 prepared were anatase when the sintering temperature increases from 600 °C to 800 °C; all of the particles size were about 1μm, the monodispersity of the particles were optimal and the particles were coated evenly, smoothly. Keywords: TiO2; SiO2; core-shell structure

Solid state synthesis of LiFePO4 studied by in situ high energy X-ray diffraction

2011 ◽  
Vol 21 (15) ◽  
pp. 5604 ◽  
Author(s):  
Zonghai Chen ◽  
Yang Ren ◽  
Yan Qin ◽  
Huiming Wu ◽  
Shengqian Ma ◽  
...  
Keyword(s):  
Solid State ◽  
High Energy ◽  
Solid State Synthesis ◽  
X Ray Diffraction ◽  
X Ray

Structural changes in titanium dioxide nanocrystals during plastic deformation

2005 ◽  
Vol 38 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Ulrich Gesenhues
Keyword(s):  
Structural Changes ◽  
Crystal Size ◽  
Lower Layer ◽  
High Energy ◽  
Primary Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hall Method ◽  
Means Of Transmission

The polygonization of 200 nm rutile crystals during dry ball-milling at 10gwas monitored in detail by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). The TEM results showed how to modify the Williamson–Hall method for a successful evaluation of crystal size and microstrain from XRD profiles. Macrostrain development was determined from the minute shift of the most intense reflection. In addition, changes in pycnometrical density were monitored. Accordingly, the primary crystal is disintegrated during milling into a mosaic of 12–35 nm pieces where the grain boundaries induce up to 1.2% microstrain in a lower layer of 6 nm thickness. Macrostrain in the interior of the crystals rises to 0.03%. The pycnometrical density, reflecting the packing density of atoms in the grain boundary, decreases steadily by 1.1%. The results bear relevance to our understanding of plastic flow and the mechanism of phase transitions of metal oxides during high-energy milling.

Unprecedented Hexa- and Undecanuclear Frameworks of Two New Tin(IV) Oxo Clusters Resulting from Partial Debenzylation Reactions

2010 ◽  
Vol 65 (11) ◽  
pp. 1293-s1308 ◽  
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey ◽  
Philippe Richard
Keyword(s):  
Solid State ◽  
1H Nmr Spectroscopy ◽  
Trifluoromethanesulfonic Acid ◽  
Synthetic Route ◽  
State Structure ◽  
X Ray Diffraction ◽  
Neutral Cluster ◽  
Broad Resonance ◽  
X Ray ◽  
The Core

A new and facile synthetic route to the known neutral cluster ((PhCH2)2SnO)6[((PhCH2)2SnOH)2- (CO3)]2 (2) as well as its reactivity toward trifluoromethanesulfonic acid (HO3SCF3, TfOH) are reported. The solid-state structure of the new solvate 2·6C7H8 has been determined by single-crystal X-ray diffraction. The core of 2 can be described as a pair of coplanar pentanuclear [(PhCH2)2SnO]5 ladders bridged at their ends by two carbonate groups. Successive additions of TfOH to a suspension of 2 in CD3CN were monitored by 119Sn{1H} NMR spectroscopy showing the transformation of the fingerprint of 2 (δ = −244, −246, −306 ppm), via new upfield signals, to a final broad resonance located at δ = −474 ppm. Thereafter, two unprecedented ionic monobenzyltin(IV) oxo clusters, 3 and 4, resulting from a debenzylation reaction and exhibiting unusual hexa- and undecanuclear frameworks, respectively, have been isolated as single crystals.

Coating thickness determination in highly absorbent core–shell systems

2012 ◽  
Vol 45 (5) ◽  
pp. 906-913 ◽  
Author(s):  
Herve Palancher ◽  
Anne Bonnin ◽  
Veijo Honkimäki ◽  
Heikki Suhonen ◽  
Peter Cloetens ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Protective Layer ◽  
Test Sample ◽  
High Energy ◽  
Core Shell ◽  
Single Shot ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Particles ◽  
Potential Applications

This article describes a single-shot methodology to derive an average coating thickness in multi-particle core–shell systems exhibiting high X-ray absorption. Powder composed of U–Mo alloy particles surrounded by a micrometre-thick UO2protective layer has been used as a test sample. Combining high-energy X-ray diffraction and laser granulometry, the average shell thickness could be accurately characterized. These results have been validated by additional measurements on single particles by two techniques: X-ray nanotomography and high-energy X-ray diffraction. The presented single-shot approach gives rise to many potential applications on core–shell systems and in particular on as-fabricated heterogeneous nuclear fuels.

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